Sony XMZR704 4/3/2-Channel ZR-Series Amplifier (Black) (Discontinued by Manufacturer) Rated Power: 80W x 4 @ 2 Ohms Rated Power: 70W x 1 @ 4 Ohms High Level Sensing Power On Subsonic Filter: 6-70Hz, OFF, -12dB/Oct Low Pass Filter: 50-300Hz, -12dB/Oct High Pass Filter: 50-300Hz, -12dB/Oct